JP2003075009A - Heat pump system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump system that is constituted to improve the evaporation of a refrigerant liquid by means of an outdoor heat exchanger even when the outdoor air temperature is low when the system is operated for heating, to increase the coefficient of performance by improving the condensation of refrigerant vapor by means of the outdoor heat exchanger even when the outdoor air temperature is high when the system is operated for cooling, and to additionally increase the coefficient of performance by making wet refrigerant vapor sucked into a compressor to become dry saturated vapor or superheated vapor. SOLUTION: A heat storage tank 10 is set up between the expansion valve 5 for cooling and expansion valve 6 for heating of a fundamental refrigerating circuit and a heating medium is heated by means of the refrigerant liquid discharged from an indoor or outdoor heat exchanger (4 or 7) which works as a condenser. The outdoor air sucked into the outdoor heat exchanger 7 is heated or cooled by supplying the heated heating medium to a heat exchanger 20 installed to the inlet section of the outdoor heat exchanger 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump system, and more particularly to a heat pump system using air as a heat source.

[0002]

As is well known, heat pump systems include
The compressor, the four-way valve, the indoor heat exchanger, the expansion valve, the outdoor heat exchanger and the four-way valve are sequentially connected by a conduit, and the four-way valve and the compressor are connected by an intake conduit. As a result, during heating operation, the four-way valve is operated so that the high temperature / high pressure refrigerant vapor compressed by the compressor flows to the indoor heat exchanger side, and the high temperature / high pressure refrigerant vapor acts as a condenser. By condensing in the indoor heat exchanger and exchanging the heat of condensation with the fluid, hot water is generated or indoor air is heated to perform a heating or drying function, and the high temperature After the high-pressure refrigerant liquid is expanded by the expansion valve, the outdoor heat exchanger that acts as an evaporator evaporates air (outside air) as a heat source to lower the temperature.
After the low-pressure refrigerant vapor is drawn, the cycle of sucking in the compressor and re-compressing is repeated.

On the other hand, during the cooling operation, the four-way valve is operated so that the high-temperature / high-pressure refrigerant vapor compressed by the compressor flows to the outdoor heat exchanger side to condense the high-temperature / high-pressure refrigerant vapor. Air is condensed as a heat source in the outdoor heat exchanger that acts as a heat exchanger, the high-temperature, high-pressure refrigerant liquid condensed in the outdoor heat exchanger is expanded by the expansion valve, and then the refrigerant in the indoor heat exchanger that acts as an evaporator. When the liquid is evaporated, the heat of evaporation is absorbed by the fluid to generate cold water or cool the indoor air to perform cooling, etc., and compress the low-temperature low-pressure refrigerant vapor evaporated in the indoor heat exchanger. Repeat the cycle of inhaling with a machine and recompressing.

In the heat pump system, in the heating operation, when the outside air temperature is low when the outdoor heat exchanger uses the outdoor air as a heat source to evaporate the refrigerant liquid, frost is formed on the surface of the outdoor heat exchanger to cause the refrigerant liquid to flow. However, since the evaporation efficiency of the refrigerant is not good and the heating capacity is significantly reduced, a large amount of capacity is put into promoting the evaporation of the refrigerant liquid in the evaporator or promoting the evaporation of the refrigerant vapor sucked into the compressor.

As an example, Japanese Patent Laid-Open No. 54-45
According to Japanese Patent Publication No. 949, a refrigerant heater is installed in a heating circuit so that it can be used also as an evaporator during heating operation, and high-temperature and high-pressure refrigerant vapor compressed by a compressor is condensed by an indoor heat exchanger to make it indoors. There is disclosed a cooling / heating device in which the heating capacity is not lowered even when the outside air temperature is low by heating the room and then evaporating the refrigerant liquid depressurized by the heating depressurization mechanism by the refrigerant heater.

In Japanese Patent Publication No. 55-5017, a plurality of outdoor heat exchangers are installed, the plurality of outdoor heat exchangers are simultaneously used as condensers during cooling, and are used as evaporators during heating. The first cycle to be operated, and a part of the high-temperature and high-pressure refrigerant vapor flowing from the compressor to the indoor heat exchanger is diverted and directly introduced into the plurality of outdoor heat exchangers,
There is disclosed a heat pump type cooling / heating device including a flow path switching device that switches a second cycle in which one of the outdoor heat exchangers acts as a condenser and the other acts as an evaporator alternately.

Further, the inventor of the present invention has found that the compressor, the conversion valve,
In a refrigerant circuit in which an indoor heat exchanger, a cooling decompression mechanism, a heating decompression mechanism, and an outdoor heat exchanger are connected to a first conduit by a refrigerant gas return pipe, the indoor heat exchanger of the first conduit and the heating decompression mechanism A first heat exchanger installed between the first heat exchanger and the first heat exchanger;
The conduit is installed between the outdoor heat exchanger and the conversion valve so as to be located above the first heat exchanger, and is connected to the first heat exchanger by a connecting pipe with a valve to form a closed circuit. A second heat exchanger, the first and second heat exchangers are filled with a working fluid, and the heat from the refrigerant liquid condensed in the indoor heat exchanger is taken as a heat source into the compressor. A heat pump type air conditioner for promoting evaporation of a refrigerant liquid and a refrigerant vapor is
I made a proposal in the issue.

On the other hand, the heat pump system described above is
Since the outdoor heat exchanger evaporates the refrigerant liquid or condenses the refrigerant vapor by using the outside air as the heat source, its capacity is determined by the amount of heat transferred from the outdoor heat exchanger, and the heat transfer area of the outdoor heat exchanger is the indoor It is a fact known in the art to design the heat exchanger to have a heat transfer area of 1.2 to 1.4 times.

[0009]

By the way, the above-mentioned Japanese Patent Laid-Open Publication No. 54-45949 of Japan is designed such that the refrigerant heater can also be used as the evaporator during the heating operation. Where no specific technical means of the vessel is described, the structure of the evaporator has no other choice but to use an electric heating structure which has a small volume and is easy to install. Therefore, the maintenance cost becomes high and the Japanese Patent Publication No. 55-5017. The one described in the gazette uses a part of the high-temperature and high-pressure refrigerant vapor compressed by the compressor when the outside air temperature drops during heating and frost is formed on the outdoor heat exchanger. However, since the compressor has to have a large capacity, there is a problem that the equipment cost and the maintenance cost increase. Further, the prior patent of the present inventor also shows that when the outdoor temperature is low, the evaporation of the refrigerant liquid is not sufficient in the outdoor heat exchanger, and the auxiliary heating means should be used during the severe cold season, so that the structure is complicated and the maintenance cost is low. There is a problem that the cost is high. Not only that, but the above-mentioned patents have a problem that the evaporation coefficient of the refrigerant liquid in the outdoor heat exchanger is low during the severe cold season, resulting in a decrease in the coefficient of performance (COP) and inferior heating efficiency. is there.

When the outside air temperature is high during the cooling operation, the temperature difference between the refrigerant vapor condensed in the outdoor heat exchanger and the outside air becomes small, so that the condensation of the refrigerant vapor becomes incomplete and the cooling load decreases. In this case, the evaporation of the refrigerant liquid in the indoor heat exchanger is incomplete, so the liquid in the liquid back
k) may occur and damage the valve of the compressor,
A liquid hammer may be generated due to liquid compression, which may damage the compressor, and the product coefficient may be reduced.

As a part of solving these problems,
Although it may be considered that the outdoor heat exchanger has a large capacity, in this case, other problems such as a high material cost and a large installation area occur.

The present invention is intended to solve such a problem, and its object is to improve the evaporation of the refrigerant liquid in the outdoor heat exchanger even when the outside air temperature is low during the heating operation and to allow the outside air temperature during the cooling operation. It is an object of the present invention to provide a heat pump system capable of increasing the productive coefficient by improving the condensation of the refrigerant vapor in the outdoor heat exchanger even when the temperature is high.

Another object of the present invention is to provide a heat pump system in which the wet refrigerant vapor sucked into the compressor is dried and saturated or superheated to further increase the product coefficient.

[0014]

To achieve the above object, the present invention provides a compressor, a four-way valve, an indoor heat exchanger, a cooling expansion valve, a heating expansion valve, an outdoor heat exchanger and the four-way valve. Are sequentially connected by a conduit, the four-way valve and the compressor are connected by a suction conduit to a basic refrigeration circuit, and the conduit is installed between a cooling expansion valve and a heating expansion valve to fill a heat medium with a latent heat. A heat storage tank containing a heat storage material, a heating heat exchanger installed in the conduit penetrating the heat storage tank, and a suction pipe of the outdoor heat exchanger that is connected to the heat storage tank by a supply pipe and a return pipe with a circulation pump. The heat exchanger installed in the heat exchanger, a heat pipe in which an evaporation unit is installed on the outer periphery of the heating heat exchanger, and a heat dissipation unit connected to the evaporation unit by a connecting pipe is located outside the heat storage tank; and the suction pipe. Refrigerant that is drawn into the compressor by being installed in parallel in the heat radiation section and the heat storage tank. Providing a heat pump system including a first and a second endothermic heat exchanger which acts selectively by the temperature of the air.

[0015]

1 is a block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 is a basic refrigeration circuit. The basic refrigeration circuit 1 includes a discharge port of the compressor 2, a four-way valve 3, an indoor heat exchanger 4, a cooling expansion valve 5, a heating expansion valve 6, an outdoor heat exchanger 7 and the four-way valve 3 via a conduit 8. In this case, the four-way valve 3 and the suction port of the compressor 2 are connected by a suction conduit 9, and the indoor connection exchanger 4 is used as a condenser during heating operation.
The outdoor heat exchanger 7 acts as an evaporator, the outdoor heat exchanger 7 acts as a condenser, and the indoor heat exchanger 4 acts as an evaporator during a cooling operation.

Reference numeral 10 is a heat storage tank. The heat storage tank 10 is installed between the cooling expansion valve 5 and the heating expansion valve 6 of the conduit 8, and the conduit 8 is penetrated into the heat storage tank 10 to heat the conduit 8. The exchanger 11 is built in and the heating medium 12 is filled. And
A latent heat storage material 13 is built in the heat storage tank 10 to form a heat medium 1
The heat reduction time of 2 is extended, the temperature is maintained constant, and the heater 14 is installed on the side wall of the heat storage tank 10 to further heat the heat medium 12.

As the latent heat storage material 13, known materials such as sulfate, nitrate, phosphate, carbonate and paraffin are used.
It is intended to cause a phase change at 27 to 30 °.

Reference numeral 20 is a heat exchanger. The heat exchanger 20
Is connected to the heat storage tank 10 through the supply pipe 21 and the return pipe 22 and is integrally formed on the suction side of the outdoor heat exchanger 7 or is installed in the vicinity thereof, and the return pipe 22 is provided with a circulation pump 23. is there. When the outside air temperature is 5 ° C. or less during the heating operation, the heat exchanger 20 heats the heat medium 12 by radiating heat from the heating heat exchanger 11 and simultaneously heats the heat medium 12 while reducing the heat to the latent heat storage material 13. By circulating and preheating the outside air drawn into the outdoor heat exchanger 7 and supplying it to the outdoor heat exchanger 7, it is possible to prevent frosting of the outdoor heat exchanger 7 or to remove frost attached to it. On the other hand, during the cooling operation, when the outside air temperature is equal to or higher than the set temperature (for example, inside and outside of 30 ° C.), the heat medium 12 is circulated to cool the outside air to the outdoor heat exchanger 7 and the cooling air to the outdoor heat exchanger 7. By supplying
It improves the condensation of the refrigerant vapor.

The control circuit of the circulation pump 23 is installed on the suction side of the outdoor heat exchanger 7 and outputs a signal, for example, as shown in FIG.
24, a high temperature (for example, 30 ° C.) reference voltage is received at the “−” terminal, an output signal of the high temperature sensor 123 is received at the “+” terminal, and the magnitudes of the voltages input to both terminals are compared.
A first comparator 125 that outputs the comparison value as a logic signal
And a low temperature (5 ° C.) reference voltage at the “+” terminal and an output signal of the low temperature sensor 124 at the “−” terminal, the magnitudes of the voltages input to both terminals are compared, and the comparison value is obtained. Is output as a logic signal, an inverter 127 that receives the output signal of the second comparator 126 and inverts the logic state and outputs the inverted signal, and the output signal of the first comparator 125 or the inverter 127. An OR gate 128 that receives the logical sum operation and outputs the operation result, and a switch 129 that performs a turn-on operation to supply power to the circulation pump 23 if the operation result of the OR gate 128 is a logical high level. Consists of.

Reference numeral 30 is a heat pipe. The heat pipe 30 includes an evaporation unit 31 installed on the outer periphery of the heating heat exchanger 11, a heat dissipation unit 32 located outside the heat storage tank 10, and a connecting pipe connecting the evaporation unit 31 and the heat dissipation unit 32. 33, which is vacuum filled with working fluid such as distilled water or alcohol.

Reference numeral 40 is a first endothermic heat exchanger, and 41 is a second endothermic heat exchanger. The first endothermic heat exchanger 40 and the second endothermic heat exchanger 41 are arranged side by side in the suction conduit 9, the first endothermic heat exchanger 40 is built in the heat radiating section 32, and the second endothermic heat exchanger 41 is provided. Is built in the heat storage tank 10. And, at the inlet side of the first and second endothermic heat exchangers 40, 41, a solenoid valve 40 'which is opened by an output signal of a temperature sensor 42 installed on the suction side of the compressor 2 of the suction conduit 9,
41 ′ is installed, and when the temperature of the refrigerant vapor sucked into the compressor 2 is equal to or higher than an appropriate temperature (for example, 12 ° C.), the solenoid valve 40 ′ is opened and the refrigerant vapor sucked into the compressor 2 is radiated. In 32, the temperature is raised slightly by heating with the condensation heat of the working fluid, and when the temperature is below the proper temperature, the solenoid valve 41 ′ is opened and in the second endothermic heat exchanger 41 it is heated with the heat of the heat medium to increase the temperature. By increasing the temperature, the wet refrigerant vapor sucked into the compressor 2 is dried and saturated or superheated.

An unexplained reference numeral 51 is a fan, and 52 and 53 are check valves. In the above-described present invention, when the compressor 2 is driven after the four-way valve 3 is operated so that the refrigerant flows along the solid arrow during the heating operation, the high-temperature / high-pressure refrigerant vapor compressed by the compressor 2 becomes It flows into the indoor heat exchanger 4 that acts as a condenser and is condensed. By heating the fluid by the condensation heat, hot water is generated or an air conditioning (heating) function is performed, and the indoor heat exchanger 4 condenses. The high-temperature and high-pressure refrigerant liquid that has been discharged is checked valve 52.
Via the heating heat exchanger 11 built into the heat storage tank 10 via the heat storage tank 10 to evaporate the working fluid in the evaporation portion 31 of the heat pipe 30 and simultaneously heat the heat medium 12 to supercool it. The supercooled refrigerant liquid is expanded by the expansion valve 6 for heating, then is evaporated by the outdoor heat exchanger 7 acting as an evaporator by using the outside air as a heat source, and the low temperature and low pressure evaporated by the outdoor heat exchanger 7. After passing through the four-way valve 3, the refrigerant vapor of the first endothermic heat exchanger 40 or the second endothermic heat exchanger 40 installed in the suction pipe 9 in parallel with the heat radiation part 32 of the heat pipe 30 and the heat storage tank 10. While selectively passing through 41, the cycle of being heated by the heat of condensation of the working fluid or the heat of holding the heat medium, being saturated with steam or being superheated to vapor, and then being sucked into the compressor 2 and being recompressed is repeated.

During the cooling operation, the four-way valve 3 is operated so that the refrigerant flows along the broken line arrow, and then the compressor 2 is operated.
Driving, the high temperature / high pressure refrigerant vapor compressed in the compressor 2 flows into the outdoor heat exchanger 7 acting as a condenser and is condensed, and the high temperature / high pressure refrigerant condensed in the outdoor heat exchanger 7 is driven. The liquid is expanded by the expansion valve 5 for cooling through the check valve 53, then flows into the indoor heat exchanger 4 which functions as an evaporator and evaporates, and the heat of evaporation is absorbed by the fluid to cool the fluid. By doing so, cold water is generated or an air conditioning (cooling) function is performed, and the low-temperature low-pressure refrigerant vapor evaporated in the indoor heat exchanger 4 is passed through the four-way valve 3 and the suction conduit 9 to the compressor 2 It is inhaled and recompressed. When the cooling cycle is repeated, the heating heat exchanger 11, the first endothermic heat exchanger 40, and the second
The endothermic heat exchanger 41 performs the same function as during the heating operation.

On the other hand, when the refrigerant liquid is supercooled in the heating heat exchanger 11 during the heating and cooling operation as described above, the condensation heat of the refrigerant liquid is radiated and the working fluid filled in the evaporation portion 31 of the heat pipe 30 is discharged. When the heat medium 12 is heated at the same time as evaporation, and the temperature of the heat medium 12 becomes a phase change temperature of the latent heat storage material 13 of 27 to 30 ° C. or higher, the latent heat storage material 13 becomes a liquid and absorbs and stores heat of fusion, When the temperature becomes lower than the phase change temperature, the heat medium 12 maintains a substantially constant temperature by becoming solid and releasing heat of solidification to the heat medium.

When the outside air temperature becomes 5 ° C. or lower during the heating operation in such a state, the output signal of the low temperature sensor 124 is input to the “−” terminal of the second comparator 126. Then,
The second comparator 126 compares the magnitudes of the voltages input to the “+” terminal and the “−” terminal and compares the low level logic signal “0”.
Is output. Next, the output signal of the second comparator 126 is inverted through the inverter 127. OR gate 12
8, the switch 129 is turned “on” according to the calculation result.
Let As a result, the circulation pump 23 is driven to be stored in the heat storage tank 10, and the heat medium 12 heated by the solidification heat of the latent heat storage material 13 is supplied to the heat exchanger 20 so that the heat transfer medium around the suction portion of the outdoor heat exchanger 7 is supplied. After preheating the outside air, the outside air was taken into the outdoor heat exchanger 7. Therefore, even when the outdoor temperature is low, the outdoor heat exchanger 7 is not frosted or the frost is removed, so that the outdoor heat exchanger 7 evaporates the refrigerant liquid well. On the other hand, when the outside temperature rises above 5 ° C, the circulation pump 2
When 3 is stopped, the outside air preheating of the suction part of the outdoor heat exchanger 7 is stopped. Therefore, when the temperature is equal to or lower than the appropriate temperature for the reason such as the operation stop, the heater 14 heats it.

Further, when the outside air temperature becomes 30 ° C. or higher during the cooling operation, the output signal of the high temperature sensor 123 indicates that the first comparator 1
25 is input to the “+” terminal. The first comparator 125
Outputs a high level logic signal "1" by comparing the magnitudes of the voltages input to the "+" terminal and the "-" terminal, and the output signal of the first comparator 125 is calculated by the OR gate 128. Depending on the result, the switch 129 is turned “on”. As a result, the circulation pump 23 is driven to supply the heat medium stored in the heat storage tank 10 to the heat exchanger 20 to supply the outdoor heat supply device 7
After cooling the ambient air, it was sucked into the outdoor heat exchanger 7. Therefore, by increasing the difference between the condensation temperature of the refrigerant vapor and the outside air temperature, the condensation of the refrigerant vapor is improved, and when the outside air temperature is less than 30 ° C., the circulation pump 23
Will stop.

Although the output signal temperature of the high temperature sensor 123 is exemplified as 30 ° C. during the cooling operation, it can be increased or decreased depending on the heat transfer area of the outdoor heat exchanger 7 or the climatic condition of the outside air. The phase change temperature of the heat storage material 13 is also changed.

During the above heating and cooling operation,
When the temperature of the refrigerant vapor evaporated in the outdoor heat exchanger 7 or the indoor heat exchanger 4 is an appropriate temperature, for example, 12 ° C. or lower,
Temperature sensor 4 installed on the suction side of the compressor 2 of the suction conduit 9
Since the solenoid valve 41 'is opened by the output signal of 2, the wet refrigerant vapor is heated by the heat medium via the second endothermic heat exchanger 41, and the solenoid valve 40' is opened when the temperature is 12 ° C or higher. Therefore, the moist refrigerant vapor is heated by the heat of condensation when the working fluid is condensed in the heat dissipation portion 32 of the heat pipe 30,
Since it is dry saturated or superheated steam, liquid back and liquid hammer of the compressor do not occur.

According to the present invention, it is possible to improve the evaporation of the refrigerant liquid in the outdoor heat exchanger during the heating operation at low outside air temperature and to condense the refrigerant vapor in the outdoor heat exchanger during the cooling operation at high outside air temperature. At the same time, the reliability of the compressor can be ensured by drying and saturating the wet refrigerant vapor sucked into the compressor into saturated or superheated vapor.

[0030]

According to the first or second aspect of the present invention, a heat storage tank is installed between the expansion valve for cooling and the expansion valve for heating of the basic refrigeration circuit, and indoor or outdoor heat acting as a condenser is provided. The heat medium is heated by the refrigerant liquid discharged from the exchanger,
Since the heat medium is supplied to the heat exchanger installed in the suction part of the outdoor heat exchanger to heat or cool the outside air sucked into the outdoor heat exchanger, the outdoor heat is generated during the heating operation with a low outdoor temperature. The exchanger improves the evaporation of the refrigerant liquid,
In a cooling operation with a high outside temperature, while making the condensation of the refrigerant vapor good, the wet refrigerant vapor sucked into the compressor by the heat medium and the working fluid of the hit pipe is dried and saturated or superheated, thereby By preventing the occurrence of liquid back and liquid hammer, the product coefficient is improved, and the product coefficient is improved even when the outside temperature is low or high, so that the efficiency can be maintained excellent regardless of the season.

According to the invention described in claim 3, in addition to the effects of claims 1 and 2, the circulation pump can be satisfactorily controlled.

In addition to the effects of the first and second aspects, the invention according to the fourth aspect can favorably control the temperature of the heat storage tank.

According to the invention of claim 5, in addition to the effects of claims 1 and 2, the wet saturated steam sucked into the compressor is satisfactorily dried and saturated or superheated steam regardless of outside air or operating conditions. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a control circuit diagram of the circulation pump according to the embodiment of the present invention.

[Explanation of symbols]

1 basic refrigeration circuit, 4 indoor heat exchanger, 7 outdoor heat exchanger, 10 heat storage tank, 11 heating heat exchanger, 13 latent heat storage material, 14 heater, 20 heat exchanger, 30 heat pipe, 31 evaporation section, 32 heat radiation Parts, 40, 41 first and second endothermic heat exchangers.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3L092 AA01 AA02 AA07 AA09 BA05                       BA16 BA17 CA00 DA01 DA02                       DA03 DA17 EA02 EA16 FA17                       FA22 FA23 FA24 MA00 NA03                       NA12 NA16 PA11 PA15 TA08                       TA09 TA10 TA13 TA15 TA16                       UA03 UA04 UA11 UA34 VA04                       VA08 WA03 WA13 WA23 XA06                       XA08 XA23 YA12 YA13 YA18

Claims (5)

[Claims] 1. A compressor, a four-way valve, an indoor heat exchanger, a cooling expansion valve, a heating expansion valve, an outdoor heat exchanger and the four-way valve are sequentially connected by a conduit, and the four-way valve and the compressor are suction conduits. And a basic refrigeration circuit connected with each other, installed between the cooling expansion valve and the heating expansion valve of the conduit to be filled with a heat medium, a heat storage tank containing a latent heat storage material, and the heat storage tank penetrating the heat storage tank. A heating heat exchanger installed in the conduit, a heat exchanger connected to the heat storage tank by a supply pipe and a return pipe with a circulation pump, installed on the suction side of the outdoor heat exchanger, and on the outer circumference of the heating heat exchanger. A heat pipe in which an evaporating unit is installed and a heat radiating unit connected to the evaporating unit by a connecting pipe is located outside the heat storage tank, is installed in parallel with the suction conduit, and is incorporated in the heat radiating unit and the heat storage tank, The first and second suctions that selectively operate according to the temperature of the refrigerant vapor drawn into the compressor. Heat pump system comprising a heat exchanger. 2. The heat pump system according to claim 1, wherein the circulation pump is driven when the outside air temperature is 5 ° C. or lower or 30 ° C. or higher. 3. The circulation pump is installed on the suction side of an outdoor heat exchanger to output a high temperature sensor and a low temperature sensor, a high temperature reference voltage is a “−” terminal, and an output signal of the high temperature sensor is a “+”. A first comparator that receives the voltage at the terminals and compares the magnitudes of the voltages input to both terminals, and outputs the comparison value as a logic signal, and a low temperature reference voltage at the "+" terminal, the output of the low temperature sensor A second comparator that receives a signal at the "-" terminal, compares the magnitudes of the voltages input to both terminals, and outputs the comparison value as a logic signal; and an output signal from the second comparator. An OR gate which receives an output signal of the first comparator or the inverter and outputs an operation result, and an operation result of the OR gate is a logic high. If level, turn on The heat pump system according to claim 1 or 2, wherein the heat pump system is controlled by a control circuit including a switch for supplying power to the circulation pump. 4. The heat pump system according to claim 1, wherein a heater is attached to the heat storage tank. 5. A solenoid valve is installed on the inlet side of the first endothermic heat exchanger and the second endothermic heat exchanger, and selectively opened by a temperature sensor installed on the intake side of the compressor of the suction conduit. The heat pump system according to claim 1, wherein the heat pump system is a heat pump system.